A process for the production of mixtures of thermoplastic polymers in powder form from aqueous emulsions ofa) a thermoplastic resin, andb) a rubber-rich graft polymerin which aqueous emulsions of a) and b) having polymer contents of 15 to 50% by weight are mixed continuously or semicontinuously in separate product streams, but at the same time, with a coagulation solution at a temperature of 50.degree. to 100.degree. C. with coagulation of polymers a) and b), the product streams are combined and the polymer mixture is separated off.